There are many examples of rivet-like devices in the prior art having a head with two or more depending shank portions. The shank portions are generally insertable through an apertured workpiece and expanded by a drive pin which is inserted into a bore that passes through the head and shank portion of the device. A common problem in earlier versions is that the devices are not reusable, or if, as in some cases, they are reusable the integrity of the device is modified rendering it more difficult to use and less effective in its retention. Examples of prior art approaches to the problem of a reusable expandable fastener include U.S. Pat. No. 4,263,833, which shows a frangible threaded pin driven into the fastener by an axial blow and thereafter removable by a rotary force being applied thereto. To remove the fastener of this particular patent requires prior removal of the threaded pin. Another approach to this problem is shown in U.S. Pat. No. 3,411,397 wherein a drive pin is driven into a bifurcated fastener and the drive pin is rotatable within the fastener from a latch position to a release position to thereby permit the bifurcated portions of the shank to relax inwardly and permit the fastener to be withdrawn from the aperture. Another prior art device is shown in U.S. Pat. No. 3,765,295 wherein a frangible drive pin is driven into a fastener having a bifurcated shank portion, the shank portion including external ribs for engaging the walls of an aperture.
None of the prior art devices show a reusable fastener having a bifurcated or split shank where the drive pin, when driven into the fastener, will inhibit movement of the shank portions relative to one another, when the fastener is rotated. The prior art primarily relied upon destruction of the rivet for its removal or; in the instance of the Loudin patent removal of the fastener required the removal of the threaded drive pin.